The development and use of child restraint systems (car seats) has resulted in the reduction of mortality and morbidity to young children. There is a definite need for a harness-type restraint system for children who have outgrown their child restraint systems and are not yet ready to use the vehicle adult restraint system. Hartley associates, Inc. proposes to perform a program of research toward the development of an affordable booster seat safety system which meets existing federal standards and provides crash injury protection using the most effective state-of-the-art materials and design characteristics. This proposed booster seat safety system will be designed for children from 30 to 60 pounds and will provide head protection, will be easily positioned using currently available automotive belt systems, and will incorporate a five-point restraint system. During Phase I, the following is proposed: design the booster seat safety system, perform three-dimensional computer simulations, fabricate prototype safety systems, and perform both user and dynamic performance evaluations. At the end of Phase I, Hartley Associates, Inc. will have demonstrated the feasibility of developing a booster seat safety system that provides the same level of protection to children weighing from 30 to 60 pounds as that currently provided to children under 40 pounds. PROPOSED COMMERCIAL APPLICATION: Successful completion of Phase I will provide a testable prototype of the booster seat safety system that will demonstrate the feasibility and practicality of the concept. The Phase II effort will include further development of this prototype in a demonstrable booster seat safety system that will lead to a marketable system suitable for reduction to practice as a commercially salable item. Phase III of this program will allow for the manufacture and marketing of the developed system either through a licensing agreement with an established child restraint manufacturer or a new company created specifically for the manufacture and marketing of the proposed booster seat safety system.